L = 0.25;
lclev = L / 4;

Point(1) = {0.0*L, 0.0*L,   0.0, lclev};

Extrude {L,0,0} { 
  Point{1}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}
Extrude {0,L/2,0} { 
  Line{1}; Layers { {5,10}, {0.7,1} } ; Recombine;  
}
Extrude {0,0,L} {
  Surface{5}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}

Point(1000) = {1, 0, 0, lclev};
Extrude { {0,0,1} , {0.85,0,0} , -2*Pi/3 } { 
  Point{1000}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}

Extrude { {0,0,1} , {0.85,0,0} , -2*Pi/3 } { 
  Point{1001}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}
Extrude { {0,0,1} , {0.85,0,0} , -2*Pi/3 } { 
  Point{1003}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}

Line Loop(31) = {29,30,28};
Plane Surface(32) = {31};
Extrude {0,0,L/2} { 
  Surface{32}; Layers { {5,10}, {0.7,1} } ; Recombine; 
}
